Gases held in DOT cylinders are used in industry, in hospitals, in homes, in traveling vehicles etc. and are held under relatively high pressures in the cylinders. Each cylinder necessarily is closed with a cylinder valve to hold the pressurized gas therein. Normally this cylinder valve is connected to a regulator valve that is used to control the outward flow of gas as desired by the user after the user partially opens the cylinder valve. When the cylinder valve is damaged or for some reason needs to be replaced there is a need to immobilize the DOT cylinder without damaging the cylinder surface while applying sufficient force with a valve removal tool to unscrew the valve from the cylinder and to replace the valve to its full depth for safe operation. If the valve is mistakenly removed with high pressure gas therein the cylinder could be thrown with great force by jet action of the gas. The main objective of this invention is to provide a simple low cost unit to allow a user to not only safely immobilize cylinders of varying sizes but to also allow a user to remove and replace cylinder valves to the proper depth without damage to the cylinder surface.
The closest prior art we have found is U.S. Pat. No. 3,595,559 , filed Jun. 30, 1969 by J. F. Gettinger and entitled "Adjustable holding device". Gettinger is intended to hold an automobile bumper moveably in place to allow moving the bumper into the most desirable position for grinding, welding or pounding thereon. Our unit allows applying great force to immobilize a cylinder only in an upright position. In Gettinger a belt is tightened to hold a bumper in a horizontal position against notched plates. See lines 54 to 62 , Col. 2 of Gettinger. This is quite different than our use of a power device such as a winch and an essentially non stretchable belt to apply great force to immobilize a cylinder in an upright position against a curved surface. Gettinger also uses a spring loaded belt with a foot pedal release to hold a cylinder with the bumper holding unit mounted thereto moveably in place. The maximum force is limited to the strength of the spring. See lines 44 to 46, Col. 2 of Gettinger. This is also quite different than our use of a hand tightened winch or similar device to pull a belt with great force to immobilize an upright cylinder. Engineers have calculated that we use a force of several thousands of pounds of pressure to immobilize a cylinder.